Eve and Cassandra are nice. I think of Eve as a middle name, but it can work as a first name too, though I'd probably give her a longer name with the nn Eve. Cassandra nicknames include the ones you mentioned and also Casey, Sandi, and Andi. A friend of mine has a niece named Cassandra and they called her Adria. A bit of a stretch, but it could work I guess.

Claire always reminds me of cheerleaders and sorority girls. It's okay, but I grew up with dozens of Claires so, to me, it sounds dated, despite the fact that it's considered a classic.